We shall study the regulationof alkaline phosphatase in the mutants of Bacillus subtilis lacking some key enzymes of glycolytic an gluconeogenetic reactions. UV-irradiated and chemically-mutagenized cells will be selected for fructose-diphosphatase, phosphoenol pyruvate synthase and triosephosphoisomerase negative cells by growing in minimal medium Experiments with these mutants will elucidate the specific reactions of glycolysis and gluconeogenesis regulating repression or depression of alkaline phosphatase. Molecular multiplicity of alkaline phosphatase will be correlated with the metabolism of any specificcarbon ssurce. This will be done by comparing the biochemical properties of the enzymes purified from cells differng in growth conditions affecting aakaline phosphatase synthesis (e.g., repressed by inorganic phosphate, lactate or succinate and derepressed by inorganic phosphate starvation and by glucose and glycerol). We shall test the hypothesis that membrane-bound alkaline phosphatase of B.subtilis is either a multi-enzyme complex or a multifunctional enzyme xomplexing with regulator proteins. It will also be worth noting why physico-chemical properties of this enzyme alter in response to changes of carbon sources in the growth media. Experimental verification of this concept will stem from the analysis of biochemical properties of the protein fractions seprated at different stages of purification of the membrane-bound alkaline phosphatase. Finally, we shall show that the multienzyme nature of alkaline phosphatase is unique for this membrane bound enzyme.